Power Source Apparatus and Method of Manufacture Thereof

The present application is the U.S. National Phase under 35 U.S.C. § 371 of International Application No. PCT/JP2023/043805, filed on Dec. 7, 2023, which claims priority under 35 U.S.C. § 119 to Japanese Patent Application No. 2023-013453, filed on Jan. 31, 2023, the content of which is incorporated herein by reference in their entirety.

The present disclosure relates to a power source apparatus that retains a large number of rechargeable battery cells in a battery holder and to the power source apparatus method of manufacture.

Power source apparatus provided with a large number of battery cells that can be recharged such as lithium-ion rechargeable battery cells have been developed for driving electrical apparatus such as electric scooters, electric automobiles, and construction heavy equipment. In these power source apparatus, output voltage can be increased by connecting the rechargeable battery cells in series and charging and discharging current can be increased by connecting the battery cells in parallel. To connect the plurality of rechargeable battery cells in a given arrangement, the power source apparatus stores the battery cells in a battery holder. The battery holder is formed with a plurality of cylindrical sections to house the rechargeable battery cells, and by storing rechargeable battery cells in those cylindrical sections, a plurality of rechargeable battery cells can be retained in parallel orientation. This type of battery holder can be implemented with a split holder that is divided at the middle in the lengthwise direction of the rechargeable battery cells and holds a plurality of rechargeable battery cells by sandwiching them from both sides (e.g. refer to Patent Literature 1). The divided holder pieces of this type of battery holder are held together, for example, by screw attachment.

Meanwhile, recent demand for high capacity and high output has increased the number of rechargeable battery cells used in these types of power source apparatus. At the same time demand for compactness and reduced weight has made it necessary to reduce spacing between adjacent rechargeable battery cells. As a result, it has become difficult to secure space between cells to dispose holes for screw attachment. Accordingly, a structure has been adopted with screw holes established only around the perimeter of the battery holder and opposing surfaces of the divided holder bonded together with adhesive.

Patent Literature 1: Japanese Laid-Open Patent Publication JP 2019-083087

However, in split battery holders that hold a large number of rechargeable battery cells and limit screw-attachment to the periphery of the battery holder, reliable attachment and connection of the divided holder pieces is problematic. Particularly in split battery holders that retain a large number of rechargeable battery cells in a space-saving manner, spacing between adjacent rechargeable battery cells is reduced and attachment area of opposing holder piece surfaces is diminished making it difficult to bond the opposing surfaces together with sufficient adhesive strength. Furthermore, configurations that bond opposing holder surfaces together with adhesive have the drawback that bonding strength reduces over time to progressively increase the probability of detachment. Consequently, for a battery holder with a rectangular planar outline that is screw-attached at both ends in the lengthwise direction, insufficient adhesion in the center region can result in detachment at the middle of the battery holder and result in warping or bulging at the center region. In particular, power source apparatus used in electric vehicles and construction equipment are subject to vibration and impact shock, and in this operational environment insufficient adhesion between split holder pieces can result in detachment causing rechargeable battery cell rotation and/or poor electrical contact with the lead plates.

The present disclosure was developed to address the problems described above. Accordingly, one object of the present disclosure is to provide a power source apparatus and method of manufacture thereof that can efficiently house a plurality of rechargeable battery cells in a battery holder while securely bonding the split holder pieces together to reliably retain the rechargeable battery cells.

The power source apparatus for an embodiment of the present disclosure is provided with a plurality of rechargeable battery cells that extend in the lengthwise direction with each cell having side walls that form a circular cylindrical shape, and a battery holder that has a plurality of (cylindrical) sections to hold the plurality of rechargeable battery cells in parallel orientation. The battery holder is divided at the middle in the lengthwise direction of the rechargeable battery cells into a first holder and a second holder that join together at an intervening bonding layer. The first holder is provided with a plurality of first holder cylindrical sections that retain one end of each of the plurality of rechargeable battery cells, a first mating surface formed at the end plane of the plurality of first holder cylindrical sections, and a plurality of side wall extensions established between adjacent rechargeable battery cells in a manner extending along the sides of the battery cells protruding from the first mating surface. Battery cell exposed regions are delineated between adjacent side wall extensions where part of the side surface of each rechargeable battery cell held in a first holder cylindrical section is locally exposed. Filling grooves are formed between rechargeable battery cell side surfaces exposed through the exposed regions and the side wall extensions and adhesive that establishes the bonding layer is filled into those filling grooves. The second holder is provided with a plurality of second holder cylindrical sections that retain the other end of each of the plurality of rechargeable battery cells, a second mating surface formed at the end plane of the plurality of second holder cylindrical sections, and protruding posts disposed opposite filling grooves in the first holder projecting out from the second mating surface at the boundaries between second holder cylindrical sections. When the first and the second holder are joined together, each protruding post is inserted inside a filling groove, but the protruding posts are disposed such that no contact is made with the first mating surface or the side wall extensions. In the assembled power source apparatus, the first and second holders are joined together and the rechargeable battery cells are held in holder cylindrical sections established by the first and second holder cylindrical sections. Tips of the side wall extensions abut against the second mating surface to align the first and second holders, and protruding posts inserted in the filling grooves are embedded in adhesive to bond with the first holder and rechargeable battery cells via the bonding layer thereby adhesively bonding the first and second holders together.

The power source apparatus method of manufacture for an embodiment of the present disclosure is a method of manufacturing a power source apparatus provided with a plurality of rechargeable battery cells having circular cylindrical side walls that extend in the lengthwise direction, and a battery holder that has cell storage space that retains the plurality of rechargeable battery cells in mutually parallel disposition. The method is provided with a preparation step that prepares a first battery holder and second battery holder that make up the battery holder that is divided at the middle in the lengthwise direction of the rechargeable battery cells, a first insertion step, a filling step, a second insertion step, and a bond curing step. In more detail, the preparation step prepares a first holder provided with a plurality of first holder cylindrical sections that retain one end of the plurality of rechargeable battery cells, a first mating surface formed at the end plane of the plurality of first holder cylindrical sections, and a plurality of side wall extensions established between adjacent rechargeable battery cells in a manner extending along the sides of the battery cells protruding from the first mating surface. Exposed regions between adjacent side wall extensions locally expose part of the side walls of the rechargeable battery cells held in first holder cylindrical sections. The preparation step also prepares a second holder provided with a plurality of second holder cylindrical sections that retain the other end of the plurality of rechargeable battery cells, a second mating surface formed at the end plane of the plurality of second holder cylindrical sections, and protruding posts that protrude out from the second mating surface at boundaries between second holder cylindrical sections where valleys are formed between adjacent rechargeable battery cells. When the first and the second holder are joined together, each protruding post is inserted between adjacent side wall extensions in a manner that does not contact with the first mating surface or the side wall extensions. In the first insertion step, one end of each of the plurality of rechargeable battery cells is inserted into each of the plurality of cylindrical sections in the first holder. In the filling step, areas between rechargeable battery cell side surfaces exposed through exposed regions and the plurality of side wall extensions delineate the filling grooves and those filling grooves are filled with adhesive. In the second insertion step, the second holder is joined with the first holder while inserting the other end of each of the plurality of rechargeable battery cells into the each of the plurality of cylindrical sections in the second holder. At that time, second holder protruding posts insert into first holder filling grooves and are embedded in the adhesive in those filling grooves. In the bond curing step, the adhesive is cured to bond protruding posts to the first battery holder and rechargeable battery cells at the bonding layer, and to securely connect the first and second battery holders together. Further, in the second insertion step of the power source apparatus method of manufacture, when protruding posts are inserted into the filling grooves, they apply pressure on the adhesive to push it in a direction out of the filling grooves, and that pushes adhesive against, and bonds it with side surfaces of the rechargeable battery cells and surfaces of the first battery holder.

The power source apparatus and method of manufacture of the present disclosure has the characteristic that the battery holder can efficiently hold a plurality of rechargeable battery cells while securely bonding the two pieces of the divided holder together to reliably retain those rechargeable battery cells. In addition, the power source apparatus and method of manufacture of the present disclosure has the feature that rotation of the circular cylindrical rechargeable battery cells due to vibration or impact can be effectively prevented to prevent malfunctions caused by cell rotation.

The power source apparatus for one embodiment of the present disclosure is provided with a plurality of rechargeable battery cells that extend in the lengthwise direction with each cell having side walls that form a circular cylindrical shape, and a battery holder that has a plurality of (cylindrical) sections to hold the plurality of rechargeable battery cells in parallel orientation. The battery holder is divided at the middle in the lengthwise direction of the rechargeable battery cells into a first holder and a second holder that join together at an intervening bonding layer. The first holder is provided with a plurality of first holder cylindrical sections that retain one end of each of the plurality of rechargeable battery cells, a first mating surface formed at the end plane of the plurality of first holder cylindrical sections, and a plurality of side wall extensions established between adjacent rechargeable battery cells in a manner extending along the sides of the battery cells protruding from the first mating surface. Battery cell exposed regions are delineated between adjacent side wall extensions where part of the side surface of each rechargeable battery cell held in a first holder cylindrical section is locally exposed. Filling grooves are formed between rechargeable battery cell side surfaces exposed through the exposed regions and the side wall extensions, and adhesive that establishes the bonding layer is filled into those filling grooves. The second holder is provided with a plurality of second holder cylindrical sections that retain the other end of each of the plurality of rechargeable battery cells, a second mating surface formed at the end plane of the plurality of second holder cylindrical sections, and protruding posts disposed opposite filling grooves in the first holder projecting out from the second mating surface at the boundaries between second holder cylindrical sections. When the first and the second holder are joined together, each protruding post is inserted inside a filling groove, but the protruding posts are disposed such that no contact is made with the first mating surface or the side wall extensions. In the assembled power source apparatus, the first and second holders are joined together and the rechargeable battery cells are held in holder cylindrical sections established by the first and second holder cylindrical sections. Tips of the side wall extensions abut against the second mating surface to align the first and second holders, and protruding posts inserted in the filling grooves are embedded in adhesive to bond with the first holder and rechargeable battery cells via the bonding layer to adhesively bond the first and second holders together.

The power source apparatus described above has the characteristic that it can reliably retain a plurality of rechargeable battery cells in a battery holder that is divided into a first battery holder and a second battery holder, which are strongly bonded together, while storing the plurality of rechargeable battery cells in an efficient manner. This is because, the first battery holder has a plurality of side wall extensions between adjacent first holder cylindrical sections that protrude from the first mating surface and extend along the sides of the rechargeable battery cells, and cell exposed regions that locally expose part of the rechargeable battery cell side walls between the side wall extensions. Filling grooves are formed in regions surrounded by rechargeable battery cell side walls exposed through cell exposed regions and the side wall extensions, and those grooves are filled with adhesive that forms the bonding layer. Further, the second battery holder has protruding posts that protrude from the second mating surface in boundary regions between second holder cylindrical sections, and those protruding posts are disposed opposite the filling grooves in the first battery holder. When the first battery holder and the second battery holder are connected, protruding posts are inserted in the filling grooves in a manner that does not make contact with the first mating surface or the side wall extensions. Protruding posts inserted in the filling grooves connect with the first battery holder and rechargeable battery cells through adhesive in the bonding layer and that bonds the first and second battery holders together.

Compared to conventional structures where opposing planar surfaces of the divided battery holder are directly connected with adhesive, the configuration described above can make bonding between the first battery holder and the second battery holder stronger by increasing the surface area in contact with the bonding layer. In the power source apparatus of the present disclosure, second battery holder protruding posts are inserted into first battery holder filling grooves. In particular, since the protruding posts are disposed such that no contact is made with the first mating surface or the side wall extensions of the first battery holder, interference between first battery holder side wall extensions and second battery holder protruding posts can be reliably prevented during holder connection. As a result, the protruding posts can be reliably connected to the first battery holder through the bonding layer formed by adhesive in the filling grooves.

In this manner, in a structure where protruding posts are joined to the first battery holder via the bonding layer, the strength of the bond between protruding post side walls and the bonding layer is based on shear strength that acts parallel to the bonding surface rather than delamination strength that acts perpendicularly. As a result, second battery holder protruding posts can be joined to the bonding layer with superior bonding strength, and the bonding strength between the first battery holder and the second battery holder can be enhanced. Further, since adhesive in the filling grooves bonds not only to the first battery holder but also to the side walls of rechargeable battery cells exposed through cell exposed regions, the bonding layer can connect over wider surface area on the first battery holder side, and the first and second battery holders can be connected more robustly. In addition, by bonding filling groove adhesive with rechargeable battery cell side walls exposed through cell exposed regions, rechargeable battery cells housed in holder cylindrical sections can be prevented from rotating inside the cylindrical sections.

In another embodiment of the power source apparatus of the present disclosure, the battery holder can be provided with cell storage space configured to house a plurality of rechargeable battery cells stacked in a “log pile” arrangement.

Since the above configuration provides cell storage space to accommodate a plurality of rechargeable battery cells in a stacked arrangement similar to “log pile,” a large number of rechargeable battery cells can be efficiently held in the battery holder and this can realize higher (energy) capacity.

In another embodiment of the power source apparatus of the present disclosure, the first battery holder is provided with filling grooves disposed in triangular regions formed at the boundary of three rechargeable battery cells at vertices of a triangle viewed in plan view, and the second battery holder is provided with protruding posts disposed in triangular regions formed at the boundary of three rechargeable battery cells similarly arranged at vertices of a triangle viewed in plan view.

With this structure, first battery holder filling grooves and second battery holder protruding posts are disposed in triangular regions (triangular spaces in a “log pile” cross section) formed at boundaries between three of the plurality of rechargeable battery cells in a “log pile” arrangement that are adjacent and positioned at vertices of a triangle viewed in plan view. This allows filling grooves and protruding posts to be disposed in a space-saving manner while efficiently storing rechargeable battery cells in a “log pile” stack, and ensures reliable bonding at boundaries of the stacked rechargeable battery cells for secure connection of the first and second battery holders.

In another embodiment of the power source apparatus of the present disclosure, the first battery holder is provided with filling grooves in all the triangular regions formed at boundaries between the plurality of rechargeable battery cells held in first holder cylindrical sections, and the second battery holder is provided with protruding posts in all the triangular regions formed at boundaries between the plurality of rechargeable battery cells held in second holder cylindrical sections.

Since the first battery holder and the second battery holder are provided with filling grooves and protruding posts in all the triangular regions formed at boundaries between the plurality of rechargeable battery cells, the first and second battery holders can be joined and firmly bonded together more reliably. Further, since protruding posts are inserted into all the filling grooves in the first battery holder, the amount of adhesive filled into each filling groove can be reduced to lower manufacturing costs.

In another embodiment of the power source apparatus of the present disclosure, the first battery holder is provided with filling grooves in all the triangular regions formed at boundaries between the plurality of rechargeable battery cells held in first holder cylindrical sections, and the second battery holder is provided with protruding posts in selected triangular regions formed at boundaries between the plurality of rechargeable battery cells held in second holder cylindrical sections such that each rechargeable battery cell is adjacent to at least one protruding post.

In this configuration, the first battery holder is provided with filling grooves in all the triangular regions formed at boundaries between the plurality of rechargeable battery cells, and the second battery holder is provided with protruding posts in triangular regions selected such that each rechargeable battery cell is adjacent to at least one protruding post. This has the characteristic that while the number of protruding posts can be reduced, all the rechargeable battery cells can be stably held in the first and second battery holders securely connected through the bonding layer formed around protruding posts adjacent to each rechargeable battery cell.

In another embodiment of the power source apparatus of the present disclosure, the battery holder has a rectangular shape in plan view extending in one direction, and the first battery holder and the second battery holder are screw connected with fastening screws at both lengthwise ends of the battery holder and are bonded together via protruding posts and the bonding layer at least in the center region in the lengthwise direction of the battery holder.

In another embodiment of the power source apparatus of the present disclosure, the bonding layer is joined not only to the protruding posts but also to the second mating surface of the second battery holder. With this configuration, surface area for contact between the bonding layer and the second battery holder is increased for more effective bonding.

In another embodiment of the power source apparatus of the present disclosure, the protruding posts have a circular cylindrical or polygonal cylindrical (prismatic) shape. Further, in another embodiment of the power source apparatus of the present disclosure, the protruding posts are shaped with ridges or grooves that extend in the lengthwise direction on cylindrical side surfaces. These types of structures increase the surface area of the protruding posts to enhance bonding strength between the protruding posts and the bonding layer.

In another embodiment of the power source apparatus of the present disclosure, the protruding posts have a conical frustum (truncated cone) or frustum of a polygonal cone (truncated polygonal cone) shape that narrows in cross sectional area towards the tip. This structure has the characteristic that protruding posts can be inserted into the filling grooves and embedded in adhesive with little initial resistance due to small cross-sectional area near the tips. As insertion continues, larger cross sectional area at the aft ends of the protruding posts gradually increases pressure on adhesive in the filling grooves to push it outward from the protruding posts.

The power source apparatus method of manufacture for one embodiment of the present disclosure is a method of manufacturing a power source apparatus provided with a plurality of rechargeable battery cells having circular cylindrical side walls that extend in the lengthwise direction, and a battery holder that has cell storage space that retains the plurality of rechargeable battery cells in mutually parallel disposition. The battery holder is divided in the middle in the lengthwise direction of the rechargeable battery cells into a first battery holder and a second battery holder. The method includes a preparation step that prepares the first battery holder and the second battery holder. The first battery holder is provided with a plurality of first holder cylindrical sections each configured to store one end of a rechargeable battery cell, a first mating surface established at the interconnected end plane of the plurality of first holder cylindrical sections, and a plurality of side wall extensions formed between adjacent rechargeable battery cells protruding from the first mating surface and extending along the side walls of the rechargeable battery cells. Cell exposed regions are delineated between the side wall extensions where part of the side wall of each rechargeable battery cell stored in a first holder cylindrical section is locally exposed. The second battery holder is provided with a plurality of second holder cylindrical sections each configured to store the other end of a rechargeable battery cell, a second mating surface established at the interconnected end plane of the plurality of second holder cylindrical sections, and a plurality of protruding posts formed protruding from the second mating surface in boundary regions that are valleys between adjacent rechargeable battery cells in second holder cylindrical sections. The protruding posts are disposed such that when the first and second battery holders are connected, the protruding posts are inserted between a plurality of side wall extensions while in a non-contact state with the first mating surface and the side wall extensions. The method includes a first insertion step where one end of each of the plurality of rechargeable battery cells is inserted into the plurality of first battery holder cylindrical sections, a filling step where filling grooves surrounded by rechargeable battery cell side walls exposed through cell exposed regions and the side wall extensions are filled with uncured adhesive, a second insertion step where the second battery holder is connected to the first battery holder while inserting the other end of each of the rechargeable battery cells into the plurality of second holder cylindrical sections while simultaneously inserting second battery holder protruding posts into first battery holder filling grooves to embed the protruding posts in adhesive in the filling grooves, and a bond curing step where the adhesive is cured to bond the protruding posts to the first battery holder and the rechargeable battery cells via adhesive in the bonding layer to bond the first battery holder and the second battery holder together. In the second insertion step, each protruding post inserted in a filling groove applies pressure on adhesive in the filling groove to force it in an outward direction, and this presses adhesive against rechargeable battery cell side walls and first battery holder surfaces for bond connection.

In the second insertion step that connects the first battery holder and the second battery holder in the method of manufacture described above, adhesive in the filling grooves is pressed by the protruding posts pushing it in a direction outward from the filling grooves. By pressing and bonding adhesive to rechargeable battery cell side walls and to surfaces of the first battery holder, the bonding layer can bond more robustly with the first battery holder and the rechargeable battery cells to increase the bonding strength between the first and second battery holders.

In another embodiment of the power source apparatus method of manufacture of the present disclosure, the amount of adhesive used in the filling step is set such that some of the adhesive pushed outward by the protruding posts in the second insertion step reaches the second mating surface of the second battery holder, and in the bond curing step, the bonding layer is bonded to the second mating surface.

Accordingly, since the amount of adhesive used in the filling step is set so that some of the adhesive pushed outward by the protruding posts in the second insertion step reaches the second mating surface of the second battery holder, the bonding layer is bonded to the second mating surface in the bond curing step, and that has the characteristic that the first battery holder and the second battery holder are more firmly attached together.

In another embodiment of the power source apparatus method of manufacture of the present disclosure, some of the adhesive pushed outward by the protruding posts in the second insertion step is pressed into gaps between the rechargeable battery cells and cell storage space walls.

According to the method described above, since some of the adhesive pushed outward by protruding posts inserted into filling grooves in the second insertion step is pressed in between rechargeable battery cells and cell storage space walls, side walls of the rechargeable battery cells bond with inside surfaces of the cell storage space over a wide area to enable stronger holder connection and more effective prevention of rechargeable battery cell rotation.

The following describes embodiments of the present disclosure in detail with reference to the figures (drawings). However, embodiments described below are merely examples intended to illustrate technical concepts of the present disclosure and the present disclosure is not limited to those examples. Further, components cited in the claims are in no way limited to the components in the embodiments. Unless specifically stated otherwise, dimensions, materials, shapes, relative disposition, and other aspects of the components described below are merely illustrative and are not intended to limit the scope of the disclosure. Note that the size, positional relationships, and other characteristics of components shown in the drawings may be exaggerated for the purpose of clear explanation. Moreover, identical names and reference numbers in the following descriptions indicate identical or similar components, and their detailed explanations may be omitted as appropriate. Furthermore, elements of the present disclosure may be configured such that a plurality of elements combine to form a single component that serves a plurality of functions, and conversely, a plurality of elements can implement a single function.

The power source apparatus of the present disclosure can be used, for example, in construction machinery; as the driving power source in hybrid and electric vehicles, electric scooters (e.g. home delivery scooters), electric carts used at golf courses, factories, and airports; as the power source in self-propelled delivery robots; and as the power source in electric assist bicycles. It can also be used as the power source in portable electric equipment such as wireless communication devices, electric vacuum cleaners, and electric hand tools. Alternatively, it can be used as a stationary power storage device for computer server backup power, or as a power source used in the household, office, and factory. The following describes a power source apparatus used as the driving power source in a construction machine as one embodiment of the present disclosure.

1 11 FIGS.- 1 FIG. 2 FIG. 1 FIG. 3 FIG. 2 FIG. 4 FIG. 5 FIG. 3 FIG. 6 FIG. 1 FIG. 7 FIG. 6 FIG. 8 FIG. 9 11 FIGS.- 100 show the power source apparatusfor embodiment 1 of the present disclosure. In these figures,is an oblique view of the power source apparatus,is an exploded oblique view of the power source apparatus in,is an exploded oblique view of the battery module in the power source apparatus shown in,andare an exploded oblique view and an exploded oblique view viewed from below of the battery holder shown in,is an enlarged horizontal cross section through the line VI-VI in the power source apparatus shown in,is a vertical cross section through line VII-VII in the power source apparatus shown in,is an exploded oblique view showing the connecting structure between the first and second holders, andare exploded cross sections and an enlarged cross section showing the connecting structure between the first and second holders.

100 1 2 3 1 2 1 2 2 4 100 5 2 1 9 9 17 10 The power source apparatusshown in these figures is provided with a plurality of rechargeable battery cellsand a battery holderthat has cell storage spaceto hold the plurality of rechargeable battery cellsin parallel orientation. The battery holderis divided at the middle in the lengthwise direction of the rechargeable battery cellsinto a first battery holderA and a second battery holderB that are joined together at an intervening bonding layer. In addition, the power source apparatusshown in the figures has a plurality of lead platesdisposed on both surfaces (upper and lower surfaces in the figures) of the battery holderthat connect the plurality of rechargeable battery cellsin a given configuration to form a battery module. The battery moduleand a circuit boardare housed in an outer case.

100 2 1 2 2 4 2 2 100 2 2 4 The power source apparatusof the present disclosure is characterized in that the battery holderthat houses a plurality of rechargeable battery cellsis divided into a first battery holderA and a second battery holderB, which are bonded together at an intervening bonding layer. Accordingly, other than the connecting structure between the first battery holderA and the second battery holderB, the power source apparatusof the present disclosure can be configured according to any existing structure or structure developed in the future. The following describes in detail the connecting structure that joins the first battery holderA and the second battery holderB at the bonding layer.

1 1 1 1 1 1 1 1 x x a b. Each rechargeable battery cellis a circular cylindrical rechargeable battery, which has an exterior container with a circular cylindrical outline. One example of a circular cylindrical rechargeable battery cellhas an electrode assembly inserted in a metal cylindrical exterior can that is filled with electrolyte and hermetically sealed with a sealing plate to close off the open end of the can. Positive and negative electrodesare established at both ends in the lengthwise direction of the circular cylindrical rechargeable battery cell. The bottom end plane of the cylindrical can and the center electrode disposed in the center of the sealing plate serve as the negative and positive electrodes. In the rechargeable battery cellsin the figures, one of the end plane electrodesis designated as the first electrode, which is disposed at the center of the sealing plate, and the other end plane electrode at the bottom of the cylindrical can is designated as the second electrode

1 This type of Rechargeable battery cellcan be a high energy efficient non-aqueous electrolyte rechargeable battery and, for example, lithium-ion rechargeable batteries can be used with good results. However, the power source apparatus of the present disclosure is not limited to lithium-ion rechargeable batteries. Any type of batteries that can be recharged such as nickel-metal hydride batteries and nickel-cadmium batteries can be used as the rechargeable battery cells.

2 20 1 1 20 3 2 1 1 2 1 2 20 1 2 c x 4 5 FIGS.and The battery holderis provided with a plurality of holder cylindrical sectionsthat house each of the rechargeable battery cellsand cover the cell side walls. The interior of each holder cylindrical sectionserves as cell storage space. The battery holdershown inholds a plurality of rechargeable battery cellsin a parallel orientation with the two end plane electrodesaligned in respective planes. The battery holderin the figures has a box shaped outline with the plurality of rechargeable battery cellsdisposed in multiple rows and columns. The battery holderis made of resin molded in a shape that establishes cylindrical sectionsin multiple rows and columns to hold the rechargeable battery cellsin multiple rows and columns. Preferably, the battery holderis made of material with superior insulating and heat resistant properties such as polycarbonate or ABS (Acrylonitrile Butadiene Styrene) resin.

2 3 1 1 1 2 1 4 6 FIGS.- The battery holdershown inis provided with cell storage spacethat holds the plurality of rechargeable battery cellsin a “log pile” cross section as viewed in a plan view. In this “log pile” configuration, gaps (valleys) between adjacent rechargeable battery cellsin one row are filled by the (peaks of) battery cellsin an adjacent row to implement space-efficient storage. Accordingly, by adopting this “log pile” arrangement, the battery holdercan efficiently house a large number of rechargeable battery cellsand realize high (energy) capacity.

2 160 1 10 1 1 2 The battery holderin the figures holdsrechargeable battery cellswith 16 cells in each laterally extending row androws stacked fore and aft. The 16 rechargeable battery cells in each row are laterally offset to position the circular side surface (peak) of the rechargeable battery cellin one row in the gap (valley) between adjacent cells in the neighboring row and establish a “log pile” arrangement in the fore and aft direction. However, the present disclosure does not limit the number or arrangement of rechargeable battery cellshoused in the battery holderto that described above. In the power source apparatus of the present disclosure, the number and arrangement of rechargeable battery cells can be adjusted according to the intended application.

2 2 2 1 4 The battery holderin the figures is divided into the first battery holderA and the second battery holderB at the midpoint in the lengthwise direction of the rechargeable battery cellsand joined together at the intervening bonding layer.

2 21 1 22 21 23 1 22 1 1 24 23 1 1 21 2 21 26 c c 4 5 FIGS.and The first battery holderA is provided with a plurality of first holder cylindrical sectionsthat hold one end of each of the plurality of rechargeable battery cells, a first mating surfaceformed by the interconnected surface at the end plane of the plurality of first holder cylindrical sections, and a plurality of side wall extensionsestablished between adjacent rechargeable battery cellsin a manner protruding from the first mating surfaceand extending along the side wallsof the rechargeable battery cells. Battery cell exposed regionsare created between each pair of adjacent side wall extensionswhere part of the side wallof each rechargeable battery cellheld in a first holder cylindrical sectionis locally exposed. The first battery holderA inis formed by integrally molding a plurality of parallel interconnected first holder cylindrical sectionswith an end plane plateat one end.

23 22 2 23 1 21 21 23 21 1 23 21 1 23 1 4 FIG. The side wall extensionshave the form of ribs that project out from the first mating surfaceof the first battery holderA. Side wall extensionsare disposed between adjacent rechargeable battery cellsand are integrally molded with first holder cylindrical sectionsin a manner extending out from the cylindrical sections. Side wall extensionthickness is essentially the same as the walls of the first holder cylindrical sectionsand is equivalent to the spacing between adjacent rechargeable battery cells. Further, as shown in, side wall extensionscurve around the cylindrical sectionswith concavity that mates with the outside surfaces of the rechargeable battery cellsto stably support of the cells. Side wall extensionsdisposed between adjacent rechargeable battery cellsserve to suppress thermal conduction between cells.

4 11 FIGS.- 8 FIG. 24 23 2 24 1 1 21 24 23 21 24 2 23 21 22 21 c As shown in, cell exposed regionsare established between adjacent side wall extensionsin the first battery holderA and those cell exposed regionslocally expose part of the side wallof each rechargeable battery cellheld in a first holder cylindrical section. Cell exposed regionsinare established between side edges of adjacent side wall extensionsand edges of first holder cylindrical sectionopenings. Each exposed regionhas a rectangular shape that curves to conform with the side wall of a rechargeable battery cell. In the first battery holderA shown in the figures, side wall extensionsare integrally formed with first holder cylindrical sectionsprotruding out from the first mating surface, which is the end plane of the first holder cylindrical sections.

23 1 22 23 24 1 1 c The protruding side wall extensionsextend in the lengthwise direction of the rechargeable battery cells. The first mating surfaceis exposed between each pair of adjacent side wall extensionsand this area is designated as cell exposed regionwhere part of the rechargeable battery cellside wallis locally exposed.

6 11 FIGS.- 2 41 1 1 24 23 40 4 41 2 24 23 40 41 1 1 24 4 1 1 1 c c c As shown inand as described above, the first battery holderA has filling groovesformed in regions surrounded by rechargeable battery cellside wallsexposed through cell exposed regionsand multiple side wall extensions. Adhesivethat forms the bonding layeris filled into the filling grooves. First battery holderA structure that establishes cell exposed regionsbetween adjacent side wall extensionsallows adhesivein the filling groovesto bond with side wallsof the rechargeable battery cellsexposed through the cell exposed regions. This attaches the bonding layerto the rechargeable battery cellside wallsand has the characteristic that rechargeable battery cellrotation can be prevented.

4 6 FIGS.- 2 1 21 2 1 25 41 41 25 1 41 1 25 41 As shown in, the first battery holderA holds rechargeable battery cellsin a plurality of first holder cylindrical sectionsarrayed in a “log pile” configuration. When the first battery holderA is viewed in plan view, the common boundary between three adjacent rechargeable battery cellsdisposed at the vertices of a triangle takes the form of a triangular regionwhere a filling grooveis established. Since this configuration disposes filling groovesin the triangular regionslocated at common boundaries between rechargeable battery cellsheld in a “log pile” arrangement, filling groovescan be disposed in a space saving manner while efficiently holding a large number of rechargeable battery cellsin a “log pile” arrangement. (Triangular regionfilling groovescorrespond to spaces in the “log pile” cross section.)

4 6 FIGS.- 2 41 25 1 21 40 41 1 1 24 1 4 3 2 41 25 4 1 c As shown in, the first battery holderA has filling groovesestablished in all the triangular regionsat boundaries between each of the plurality of rechargeable battery cellsheld in first holder cylindrical sections. In this structure, adhesivein the filling groovesbonds with the side wallsof rechargeable battery cellsexposed through cell exposed regions. Rechargeable battery cellsthat are bonded with the bonding layerare prevented from rotating inside the cell storage space. Since the first battery holderA shown in the figures has filling groovesin all of the triangular regions, it has the characteristic that the bonding layeris joined with all the rechargeable battery cellsheld in the battery holder to effectively prevent any of them from rotating.

2 23 22 24 1 1 21 23 1 24 2 4 1 3 20 c As described above, the first battery holderA is provided with a plurality of side wall extensionson the first mating surface, and cell exposed regions, which locally expose part of the side wallof each rechargeable battery cellhoused in a first holder cylindrical section, are formed between adjacent side wall extensions. By bonding parts of the rechargeable battery cellsthat are exposed through cell exposed regionsto the first battery holderA at the bonding layer, cylindrical rechargeable battery cellsheld in the cell storage spaceare prevented from rotating inside the holder cylindrical sections.

2 23 41 4 33 4 24 23 1 23 41 4 40 41 41 23 41 23 40 41 23 40 2 In the first battery holderA described above, increasing the protrusion height (H) of the side wall extensionsincreases the depth (D) of the filling grooveswhere the bonding layeris formed and increases bonding area between the subsequently described protruding postsand the bonding layerto increase bonding strength. Further, by increasing the area of the cell exposed regionsformed between adjacent side wall extensions, bonding with the rechargeable battery cellscan be strengthened. Conversely, if the protrusion height (H) of the side wall extensionsis decreased, the depth (D) of the filling groovesthat form the bonding layerdecreases and the amount of adhesivenecessary to fill the filling groovescan be reduced to lower manufacturing cost. Accordingly, considering these factors and mold release constraints during resin molding, filling groovedepth (D) and side wall extensionprotrusion height (H) can be set within a range from 2 mm to 10 mm and preferably from 4 mm to 6 mm. In addition, filling groovedepth (D) and side wall extensionprotrusion height (H) are set to result in a bonding surface area that provides sufficient adhesive strength for vibration test requirements. Adhesivebonding surface area set by the filling groovesand side wall extensionsis determined based on the required bonding strength. For example, minimum adhesivebonding surface area is made greater than or equal to 50 mm.

23 1 24 4 1 23 24 4 1 23 24 2 23 24 2 6 FIG. If side wall extensionwidth (W) is increased, heat conduction between adjacent rechargeable battery cellscan be effectively suppressed. However, this narrows the width(S) of the cell exposed regionsand reduces bonding area between the bonding layerand the rechargeable battery cells. Conversely, If side wall extensionwidth (W) is decreased, cell exposed regionwidth(S) increases and the bonding area between the bonding layerand the rechargeable battery cellsincreases, but this decreases the effectiveness of heat conduction suppression between adjacent rechargeable battery cells. Accordingly, side wall extensionwidth (W) and cell exposed regionwidth(S) are set considering these trade-offs. In the first battery holderA shown in, the ratio W:S of side wall extensionwidth (W) to cell exposed regionwidth(S) is approximately 2:3. However, in the first battery holderA, the value of the ratio (W/S) of the side wall extension width (W) to the cell exposed region width(S) can be set within a range from ¼ to 3 and preferably from ⅖ to 2.

2 1 1 23 23 24 23 1 24 1 2 1 23 1 24 1 6 FIG. The first battery holderA shown inholds rechargeable battery cellsin a “log pile” arrangement, and each rechargeable battery cellhas six side wall extensionsdisposed at equal intervals around the cell perimeter (circumference). Here, the ratio of the width (W) of the side wall extensionsto the width(S) of the cell exposed regionsis approximately 2:3. This makes the width (W) of the side wall extensionsapproximately 1/15 of the circumference of the rechargeable battery celland the cell exposed regionwidth(S) approximately 1/10 of the circumference of the rechargeable battery cell. Accordingly, for a first battery holderA that holds rechargeable battery cellsin a “log pile” configuration, side wall extensionwidth (W) can be set in a range from 1/30 to ⅛ of the rechargeable battery cellcircumference, and the cell exposed regionwidth(S) can be set in a range of approximately 1/24 to 2/15 of the rechargeable battery cellcircumference.

2 31 1 32 31 33 32 31 41 2 2 31 36 5 FIG. The second battery holderB is provided with a plurality of second holder cylindrical sectionsthat retain the other end of each of the plurality of rechargeable battery cells, a second mating surfaceformed by the interconnected surface at the end plane of the plurality of second holder cylindrical sections, and protruding poststhat protrude from the second mating surfaceat boundaries between a plurality of adjacent second holder cylindrical sectionsopposite filling groovesin the first battery holderA. The second battery holderB inis configured with a plurality of separate parallel interconnected second holder cylindrical sectionsintegrally molded with an end plane plateat one end.

5 8 FIGS.and 33 2 32 33 41 2 2 2 33 41 40 41 33 40 41 40 40 1 1 2 c As shown in, protruding postsare integrally formed with the second battery holderB as pillars that project out from the second mating surface. The protruding postsare designed to be inserted into the filling groovesin the first battery holderA when the first and second battery holdersA,B are joined together. Protruding postsinserted in the filling groovesare embedded in adhesivethat occupies the filling grooves. The protruding postsapply pressure on adhesivein the filling groovesin a direction that pushes the adhesiveout of the grooves. This presses adhesiveagainst the side wallsof the rechargeable battery cellsand the surface of the first battery holderA for bonding.

9 11 FIGS.- 6 9 11 FIGS.and- 33 41 40 33 41 22 2 33 33 23 41 33 41 22 23 42 33 22 40 42 43 33 23 40 43 33 41 1 1 24 44 33 1 40 44 c Further, as shown in, although protruding postsinserted in the filling groovesare embedded in adhesiveinside the grooves, the tip of each protruding postis disposed such that it does not make contact with the bottom of the filling groove, which is the first mating surfaceof the first battery holderA. Specifically, the height (h) of the protruding postis made smaller than the depth (D) of the filling groove. In addition, as shown in, side surfaces of the protruding postsare configured such that no contact is made with the side surfaces of the side wall extensions, which serve as the inside walls of the filling grooves. Namely, while the protruding postsinsert into the filling grooves, they are disposed such that no contact is made with either the first mating surfaceor the side wall extensions. In this manner, a bonding gapis formed between the tip of each protruding postand the first mating surface, and bonding is achieved via the adhesivethat fills this bonding gap. Further, bonding gapsare formed between side surfaces of the protruding postsand the side wall extensions, and bonding is also achieved via adhesivethat fills those bonding gaps. Still further, protruding postsinserted in the filling groovesare preferably designed such that no contact is made with the side wallsof rechargeable battery cellsexposed through cell exposed regions. Accordingly, bonding gapsare formed between side surfaces of the protruding postsand the rechargeable battery cells, and solid bonding is achieved via the adhesivein those bonding gaps.

33 40 41 4 33 4 4 4 33 4 33 33 41 40 40 42 22 33 22 33 40 40 43 23 44 1 1 4 2 1 2 2 33 33 33 41 42 33 22 c 2 As described above, protruding postsembedded in adhesivefilled filling grooveshave the characteristic that adhesion with the bonding layeris established over more surface area than in a conventional structure where opposing planar mating surfaces are directly joined together. This is because side surfaces of the protruding postsembedded in the bonding layeradhere closely with the bonding layer. In particular, a structure where the bonding layeris formed with adhesive in close contact with the sides of the protruding postshas the characteristic that adhesive strength between the bonding layerand the protruding postsis due to shear strength, which is more robust than delamination strength that acts in conventional bonding between opposing planar mating surfaces. Further, since protruding postsinserted into the filling groovespress into the adhesive, adhesivein the bonding gapsis pressed into and bonded with the first mating surface. This has the characteristic that the surface at the tip of each protruding postbonds to the first mating surfacewith high delamination strength. In addition, protruding poststhat press into the adhesivealso press adhesivein bonding gapswith the side wall extensionsand in bonding gapswith the side wallsof the rechargeable battery cellsfor pressure bonding with those surfaces. Accordingly, the bonding layercan be strongly bonded to the first battery holderA and the rechargeable battery cellsto increase bonding strength between the first battery holderA and the second battery holderB. Here, considering the strength of the protruding posts, protruding postminimum surface area is set, for example, greater than or equal to 15 mm. Protruding postheight (h) is set based on filling groovedepth (D) and the width of the bonding gapbetween the tip of the protruding postand the first mating surfaceis set, for example, from 0.5 mm to 1 mm.

33 40 41 33 4 33 33 33 33 4 33 5 8 FIGS.and 12 FIG. 12 FIG. a a While protruding postsembedded in adhesivein the filling groovescan have smooth surfaces as shown in, changing surface shape or conditions at the tip and sides of the protruding postscan result in even stronger bonding with the bonding layer. The protruding postA shown inhas ridges (ribs)formed in a plurality of rows that extend in the lengthwise direction on the cylindrical side surface. Although not illustrated, a plurality of rows of grooves can also be formed extending in the lengthwise direction on the cylindrical side surface. In this way, ridgesor grooves formed on the side surface of the pillar shaped protruding postA increases its overall surface area and enhances bonding strength with the bonding layer. Although the surface of the tip of the protruding postA is shown as a smooth surface in, it can also be an uneven non-planar surface. For example, a plurality of rows of ridges or grooves can be provided on the tip of the protruding post.

33 33 23 33 1 33 35 2 2 41 33 33 23 33 33 1 4 13 FIG. 13 FIG. 13 FIG. b c d b e c Further, the protruding posts can also be polygonal cylinders (prisms) with a polygonal cross-section. A polygonal cylindrical protruding post has the characteristic that its surface area is greater than that of a corresponding circular cylindrical protruding post. The protruding postB shown in the bottom view ofis a polygonal cylinder with a hexagonal cross-section. Of the six sides of the hexagonal cross-section shown in, three sidesare disposed facing side wall extensionsand the remaining interposed three sidesface rechargeable battery cells. This configuration allows the protruding postB to efficiently utilize the area available in the triangular regionof the second battery holderB, while also allowing it to be inserted without excessive force into a first battery holderA filling groove. Further, as shown by the broken lines in, the hexagonal cross-section protruding post can also be provided with ridgesor grooves (not illustrated) on the sidesthat face the side wall extensions, and the protruding post can be provided with grooveson the sidesthat face the rechargeable battery cells. This structure can further increase protruding post surface area and enhance bonding strength with the bonding layer.

14 FIG. 33 33 41 33 In addition, as shown in, the protruding postC can be shaped as a conical frustum (truncated cone) that narrows in cross sectional area towards the tip. Since a protruding postC with this shape has a smaller cross sectional area at the tip, it can be inserted into a filling groovewith little initial resistance. As insertion continues, larger cross sectional area at the aft end of the protruding postC gradually increases pressure in directions outward from the protruding post.

Although not illustrated, the protruding post can also be formed as the frustum of a polygonal cone (truncated polygonal cone) that narrows in cross sectional area towards the tip. In addition, even for the case of a protruding post that gradually narrows in cross sectional area towards the tip, surface area can be increased by establishing ridges or grooves on the side surfaces.

2 2 33 22 2 23 32 2 2 23 32 2 2 33 22 2 2 2 23 1 32 33 22 2 33 22 2 2 23 32 42 33 22 40 As described above, when the first battery holderA and the second battery holderB are connected together with the tips of the protruding postsin a non-contact state with respect to the first mating surface, first battery holderA side wall extensiontips make contact with the second mating surfaceof the second battery holderB and align the battery holder assembly. Said differently, when first battery holderA side wall extensionsbutt against the second mating surfaceof the second battery holderB and align the assembly, second battery holderB protruding postsare configured such that they do not contact the first mating surfaceof the first battery holderA. With this structure, the second battery holderB can be joined with the first battery holderA while aligning the mating surfaces by butting the ends of side wall extensions, which surround each of the plurality of rechargeable battery cells, against the second mating surface. If protruding postswere instead designed to simultaneously butt against the first mating surfaceof the first battery holderA, alignment during connection of the first and second battery holders would be required on two different reference surfaces, and due to molding tolerances, there would be risk of misalignment. In contrast, with the structure of the present disclosure where protruding postsare in a non-contact state with respect to the first mating surface, first battery holderA and second battery holderB mating surfaces can be accurately positioned via the ends of the side wall extensionsand the second mating surface. Furthermore, by forming bonding gapsbetween the ends of the protruding postsand the first mating surface, adhesiveresiding in the bonding gaps can create reliable bonding and strong battery holder attachment.

40 41 33 41 2 23 32 2 40 41 33 40 32 2 40 41 33 41 33 33 40 41 40 32 2 4 32 40 23 32 23 32 2 32 40 Here, the amount of adhesivein the filling groovesis preferably adjusted such that when protruding postsare inserted in the filling groovesand the ends of first battery holderA side wall extensionsbutt against the second mating surfaceof the second battery holderB, adhesivein the filling groovesis pushed upward due to protruding postinsertion and the upper surface of the adhesivecoincides with the second mating surfaceof the second battery holderB. Specifically, the amount of adhesivefilled into the filling groovesprior to protruding postinsertion is preferably equal to or slightly greater than the volume of the filling groovesminus the volume of the protruding posts. In this way, when protruding postsare inserted into adhesivefilled filling grooves, the upper surface of the adhesivecontacts the second mating surfaceof the second battery holderB and joins the bonding layerwith the second mating surface. Further, adhesivecan also reside between tips of the side wall extensionsand the second mating surface. In this case, tips of the side wall extensions, which butt against the second mating surfaceof the second battery holderB, are bonded to the second mating surfacevia interposed adhesive.

2 1 35 33 35 33 35 1 33 2 33 35 1 31 2 33 35 31 33 41 35 25 1 2 2 2 33 2 41 2 40 41 5 FIG. When the second battery holderB is viewed in plan view, the common boundary between three adjacent rechargeable battery cellsdisposed at the vertices of a triangle forms of a triangular region, and protruding postsare formed in each triangular region. In the structure described above, protruding postsare established in triangular regionsat the boundaries of the rechargeable battery cellsstored with a “log pile” cross section. Accordingly, it is possible to efficiently store a large number of rechargeable battery cells in a compact “log pile” configuration while disposing the protruding postsin a space-saving manner. The second battery holderB has protruding postsprovided in the triangular regionsat the boundaries between rechargeable battery cellshoused in second holder cylindrical sections. The second battery holderB shown inhas protruding postsestablished in all the triangular regionsat boundaries between second holder cylindrical sections. Since protruding postsand filling groovesare provided in all the triangular regions,at the boundaries between rechargeable battery cellsin this type of battery holder, it has the characteristic that the first battery holderA and the second battery holderB can be reliably connected and strongly attached. Moreover, since protruding postsare inserted into all of the first battery holderA filling grooves, the battery holderhas the characteristic that the amount of adhesivefilled into each filling groovecan be reduced to lower manufacturing cost.

2 33 35 31 35 33 1 33 33 1 33 2 2 4 1 15 FIG. However, the second battery holder does not necessarily have to have protruding posts in all of the triangular regions, and instead protruding posts can be provided only in selected triangular regions. The second battery holderB shown inis configured with protruding postsestablished only in selected triangular regionsat the boundaries between rechargeable battery cells housed in second holder cylindrical sections. Here, the triangular regionswhere protruding postsare established are selected such that each rechargeable battery cellis adjacent to at least one protruding post. With this structure, the number of protruding postsis reduced making assembly more efficient. At the same time, since each rechargeable battery cellis adjacent to a protruding post, it has the characteristic that the first battery holderA and the second battery holderB can be reliably connected via the bonding layerwhile stably retaining all of the rechargeable battery cells.

2 2 2 39 2 2 2 39 2 2 38 39 2 28 38 39 39 2 2 2 2 2 2 33 4 2 2 33 2 4 5 FIGS.and Further, the battery holdershown inhas the first battery holderA and the second battery holderB fastened together at the perimeter with fastening screws. The battery holdershown in the figures has the shape of a box, which is rectangular in plan view extending in length in one direction. The first battery holderA and the second battery holderB are connected together with fastening screwsat both ends in the lengthwise direction of the battery holder. The second battery holderB shown in the figures is provided with three screw insertion holesat each end to insert the fastening screws, and the first battery holderA is provided with three screw receptacle holesat each end disposed opposite the screw insertion holesto accept the fastening screws. By screw connection with fastening screwsat both ends, this battery holderis held together with additional strength. In a structure where the first battery holderA and the second battery holderB are screwed together at the perimeter of the battery holder, the first battery holderA and the second battery holderB are attached together via protruding postsand the bonding layerat least in the central portion of the battery holder. Accordingly, the battery holdercan be configured at least with protruding postsdisposed only in the central portion of the second battery holderB.

40 4 40 40 41 21 1 40 41 40 As the adhesivethat forms the bonding layer, for example, material that is liquid or gelatinous in the uncured state can be suitably applied. By using liquid adhesivethat is preferably high in viscosity, outflow of adhesiveadded to the filling grooves, downward flow into gaps between first holder cylindrical sectionsand the rechargeable battery cells, and leakage to the outside can be prevented. Accordingly, viscosity of the adhesivein the uncured state is adjusted to be high enough to prevent it from flowing when its depth is equal to that of the filling grooves. Bonding agents such as silicone that are flame-retardant and capable of bonding with metals and resins can be used as the adhesive.

1 2 5 2 5 1 1 9 5 2 1 1 5 2 1 1 6 2 5 5 5 6 1 1 x b a 3 5 FIGS.- The plurality of rechargeable battery cellshoused in the battery holderare connected together via lead plateson the outside surfaces (upper and lower surfaces in the figures) of the battery holder. The lead platesconnect end plane electrodesof the rechargeable battery cellsto electrically connect them in series or parallel. The battery moduleshown in the figures is provided with a plurality of first lead platesA disposed on the bottom surface of the battery holderconnected to the second electrodesof the rechargeable battery cells, a plurality of second lead platesB disposed on the upper surface of the battery holderconnected to the first electrodesof the rechargeable battery cells, and a plurality of bus-bar platesthat extend vertically on the sides of the battery holderto electrically connect ends of the first lead platesA and the second lead platesB. The lead platesand bus-bar platesare made of metal plate that has superior conductivity such as nickel or aluminum. In the examples shown in, 160 rechargeable battery cellsare arranged as a series connection of 8 groups of 20 battery cells connected in parallel. However, the number and disposition of the rechargeable battery cellsas well as the number of battery cells connected series or parallel are not limited to this example and can be adapted as required.

100 1 2 5 9 9 10 100 17 9 17 1 1 17 18 2 FIG. 2 FIG. The power source apparatusshown inconnects the plurality of rechargeable battery cellshoused in the battery holdervia the lead platesto form the battery module, and the battery moduleis held in an outer case. In addition, in the power source apparatusshown inhas a circuit boarddisposed on the side of the battery module. The circuit boardis provided with charge/discharge circuitry for charging and discharging the rechargeable battery cellsand protection circuitry that monitors rechargeable battery cellvoltage and temperature and cuts off current in the event of abnormality. The circuit boardis disposed in a designated location via a circuit board holder.

1 FIG. 2 FIG. 10 9 10 10 11 12 13 14 15 16 10 10 As shown in, the outer casehas a box shaped outline with a hollow interior where the battery moduleis housed. The outer caseshown in the figures is an assembly of a plurality of plate components. The outer caseexample shown in the exploded oblique view of, is made in a box shape by connecting a top plate, left and right side platesand, front and rear end platesand, and a bottom plate. However, the outer case can also be formed as an integrated unit or with a split structure such as a divided configuration having a right and left case. The outer casedescribed above is made of material with superior strength such as metal. Alternatively, for improved insulation, the outer casecan also be made of resin material such as polycarbonate.

The following describes one example of the method of manufacture of the power source apparatus detailed above.

2 2 2 21 1 22 21 23 1 1 22 24 23 1 1 21 2 31 1 32 31 33 32 31 1 2 2 33 23 22 23 c In this step, a first battery holderA and a second battery holderB are prepared. The first battery holderA is prepared with a plurality of first holder cylindrical sectionsthat retain one end of the plurality of rechargeable battery cells, a first mating surfaceformed at the interconnected end plane of the plurality of first holder cylindrical sections, and a plurality of side wall extensionsestablished between adjacent rechargeable battery cellsin a manner extending along the sides of the rechargeable battery cellsprotruding from the first mating surface. Exposed regionsbetween adjacent side wall extensionslocally expose part of the side wallsof the rechargeable battery cellsheld in first holder cylindrical sections. The second battery holderB is prepared with a plurality of second holder cylindrical sectionsthat retain the other end of the plurality of rechargeable battery cells, a second mating surfaceformed at the interconnected end plane of the plurality of second holder cylindrical sections, and a plurality of protruding postsformed protruding out from the second mating surfacein boundary regions between adjacent second holder cylindrical sections, namely in valley regions between adjacent rechargeable battery cells. In the assembled state where the first battery holderA and the second battery holderB are joined together, each protruding postis inserted between adjacent side wall extensionsbut does not make contact with either the first mating surfaceor the side wall extensions.

1 2 21 In this step, one end of each of the plurality of rechargeable battery cellsis inserted into each of the plurality of first battery holderA cylindrical sections.

1 1 24 23 41 40 41 41 25 1 25 23 1 1 24 23 40 c c 8 FIG. In this step, regions surrounded by rechargeable battery cellside wallsexposed through cell exposed regionand the plurality of side wall extensionsdelineate the filling grooves, and uncured adhesiveis filled into those filling grooves. As shown in, filling groovesare established in the triangular regionslocated in valleys (spaces in the “log pile” cross section) between three adjacent rechargeable battery cellsdisposed at the vertices of a triangle as viewed in plan view. Each triangular regionis established by three side wall extensionsand rechargeable battery cellside wallsexposed through cell exposed regionsbetween the side wall extensions. Adhesiveis supplied in specified amount to designated positions, for example, by a scanning dispenser.

40 41 40 33 32 2 40 4 32 2 2 40 41 2 32 33 4 32 2 2 2 33 4 9 11 FIGS.- In this step, the amount of adhesivesupplied to a filling groovecan be adjusted such that some of the adhesivepushed upward by protruding postinsertion during the subsequently described second insertion step reaches the second mating surfaceof the second battery holderB (see). When adhesiverises to this level and is hardened in bond curing step described below, the bonding layerbonds with the second mating surface, to more strongly join the first battery holderA and the second battery holderB. However, the amount of adhesivein the filling groovescan also be less than that required to reach the second battery holderB second mating surfacewhen displaced by protruding postinsertion. In this case, while the bonding layerdoes not extend to the second mating surfaceof the second battery holderB, the second battery holderB will still be bonded to the first battery holderA by the protruding poststhat bond with the bonding layer.

9 11 FIGS.- 2 2 1 31 2 2 33 2 41 40 41 2 2 2 23 32 2 As shown in, in this step, the second battery holderB is joined with the first battery holderA while inserting the other end of each of the plurality of rechargeable battery cellsinto each of the plurality of cylindrical sectionsin the second battery holderB. At that time, second battery holderB protruding postsinsert into first battery holderA filling groovesand are embedded in the adhesivein those filling grooves. The first battery holderA and the second battery holderB are joined with accurate alignment by butting the ends of first battery holderA side wall extensionsagainst the second mating surfaceof the second battery holderB.

33 1 2 41 2 33 41 40 41 40 40 41 1 1 40 41 1 1 21 1 2 c c 10 FIG. At this time, the protruding postsformed in valley regions between battery cellsin the second battery holderB are inserted into the filling groovesin the first battery holderA. Protruding postsinserted in the filling groovespress into uncured adhesivein the filling groovesand push that uncured adhesiveoutward. Here, adhesivepushed out of the filling groovesflows along the side wallsof the rechargeable battery cellsas indicated by arrow A in. Since adhesiveforced out of the filling groovesis press-fit between rechargeable battery cellside wallsand the inner surfaces of first holder cylindrical sections, rechargeable battery cellsare strongly bonded with the inner surfaces of the first battery holderA.

40 1 21 41 2 40 2 1 2 33 40 41 40 1 20 40 41 1 21 1 31 1 2 2 Rather than directly dispensing adhesivebetween rechargeable battery cellsand first holder cylindrical sections, filling groovesin the first battery holderA are filled with adhesiveand the second battery holderB is then fitted over the rechargeable battery cells. When second battery holderB protruding postspress into the adhesivefilled filling grooves, adhesiveis pushed into the space between the rechargeable battery cellsand holder cylindrical sections. Therefore, depending on the amount of adhesivein the filling grooves, the adhesive may be press-fit not only between the rechargeable battery cellsand first holder cylindrical sections, but also between the rechargeable battery cellsand second holder cylindrical sections. In this case, rechargeable battery cellsare firmly attached not only to the first battery holderA, but also to the second battery holderB.

40 33 2 1 40 4 2 2 In this step, the adhesiveis cured and protruding postsare bonded to the first battery holderA and rechargeable battery cellsvia the adhesivebonding layer. This bonds the first battery holderA and the second battery holderB together.

The power source apparatus and method of manufacture of the present disclosure can be suitably used in construction machinery and as the driving power source in hybrid and electric vehicles. Further, it can be effectively utilized as the driving power source in self-propelled delivery robots, electric carts used for delivery and on golf courses, as well as in electric scooters. In addition, it can be used as the power source in electric assist bicycles, and suitably applied as the power source in portable electric devices such as wireless communication devices, electric cleaners, and electric hand tools. It can also serve as a stationary power storage device in applications such as a computer server backup power source and as a power supply system used in the household, office, and factory.

100 power source apparatus 1 rechargeable battery cell 1 x end plane electrode 1 a first electrode 1 b second electrode 1 c (battery cell) side wall 2 battery holder 2 A first battery holder 2 B second battery holder 3 cell storage space 4 bonding layer 5 lead plate 5 A first lead plate 5 B second lead plate 6 bus-bar plate 9 battery module 10 outer case 11 top plate 12 (left) side plate 13 (right) side plate 14 (front) end plate 15 (rear) end plate 16 bottom plate 17 circuit board 18 circuit board holder 20 holder cylindrical section 21 first holder cylindrical section 22 first mating surface 23 side wall extension 24 cell exposed region 25 triangular region 26 end plane plate 27 electrode window 28 screw receptacle hole 31 second holder cylindrical section 32 second mating surface 33 33 33 33 ,A,B,C protruding post 33 33 a d ,ridge 33 33 b c ,(protruding post) side 33 e groove 35 triangular region 36 end plane plate 37 electrode window 38 screw insertion hole 39 fastening screw 40 adhesive 41 filling groove 42 43 44 ,,bonding gap